Industrial Stormwater Inspection Checklist

Most stormwater inspection checklists you'll find online are construction checklists. They ask about your current phase of grading, whether your silt fences are intact, whether your construction exit is stopping track-out. Useful questions on a site that's being built.

If you operate a permitted industrial facility, those aren't the questions that determine your compliance.

This is the other checklist. It covers what an industrial facility actually gets inspected on — monthly visual observations by discharge location, exposure at the areas where industrial activity happens, minimum BMP condition, and the state of your treatment systems. Four pages, fillable, no email required.

download the checklist — PDF, 4 pages

Fillable on a phone or tablet. Prints clean if you'd rather carry a clipboard.

What's in It

Facility and Inspection Record

  • WDID
  • SIC code
  • Receiving water
  • Inspector certification
  • Current ERA level

The header fields an auditor looks for first.

Weather and Discharge

  • Rainfall
  • Storm start
  • Whether the event qualified

The qualifying storm event definition is printed on the page so you're not guessing in the rain.

Discharge Location Observations

A row per outfall for the five things you're required to look for, logged where you looked:

  • Floating and suspended material
  • Sheen
  • Discoloration
  • Turbidity
  • Odor

Industrial Activity Areas

Twelve areas worth walking, including the ones that quietly generate metals:

  • Galvanized roofing and downspouts
  • Parking and traffic surfaces
  • Uncovered material storage
  • Scrap and waste handling

Minimum BMPs

The seven required at every permitted facility, in a form somebody else can read.

Treatment Control BMPs

A row per unit that makes you write down when the media went in.

Benchmark Quick Reference

Zinc, copper, pH, TSS, and oil and grease — on one page, across:

  • California IGP
  • Washington ISGP
  • Oregon 1200-Z
  • EPA MSGP

We couldn't find that published anywhere, so we built it.

Corrective Actions and Certification

  • Findings
  • Owners
  • Due dates
  • Signature
  • Retention requirement

Ready to Walk Your Site?

All eight sections on four fillable pages. No email, no gate — take it with you on your next inspection.

download the checklist

Talk to Someone Today

We know compliance can be a headache. Reach out to us via phone, email or contact form and get started.

talk to a stormwater management engineer

What an Industrial Inspection Actually Covers

Monthly observations, qualifying storms, exposure, and treatment condition — the Gullywasher checklist walks you through all four, field by field.

download the gullywasher checklist

Monthly Visual Observations

Every month during scheduled operating hours, you walk each drainage area and each discharge location and record what you see:

  • Floating or suspended material
  • Sheen
  • Discoloration
  • Turbidity
  • Odor
  • Any non-stormwater discharge and its source

The requirement isn't the walk. It's the record. An observation you made and didn't write down is, for compliance purposes, an observation you didn't make.

Sampling Event Observations

Separate from the monthly walk, you observe and sample during qualifying storm events. Under the California IGP:

  • A QSE is at least 0.1 inch of precipitation preceded by 48 hours with no discharge
  • Samples are collected within four hours of the start of discharge or the start of your operating hours
  • Two sampled QSEs in the first half of the rain year, two in the second

Your permit governs. Confirm the thresholds against it — this checklist is a field aid, not a substitute.

Exposure, Which Is Where the Metals Come From

Most facilities know to look at their storage yard. Fewer walk the roof.

  • Galvanized roofing, gutters, and downspouts — a primary source of zinc, discharging whether or not anything else on your site is exposed
  • Parking and traffic areas — zinc and copper from brake and tire wear

Both show up in sample results as an exceedance that nobody can trace back to an activity, because there isn't one — it's the building. That's why the checklist walks areas rather than activities. It's the difference between an inspection that explains your numbers and one that doesn't.

Treatment BMP Condition

If you have treatment installed, its condition is part of your inspection:

  • Inlet clear
  • Sediment within design limits
  • No bypass or short-circuiting
  • No standing water past the drawdown period
  • Housing intact
  • Maintenance log current
  • Media within service life — the item most often missed, because it's the only one you can't see

A treatment unit past its media life still looks installed. It still passes a walkthrough. It is not treating anything. Facilities that were in compliance fall out of it this way more often than any other, and the fix is as simple as writing the install date on the form and tracking it.

Benchmark Quick Reference

This table matches page 3 of the Gullywasher Industrial Stormwater Inspection Checklist — download it and the benchmarks ride along on every inspection, next to the fields where you log your results.

Parameter CA IGP (annual NAL) WA ISGP OR 1200-Z EPA MSGP
Total zinc 0.26 mg/L 0.117 mg/L 0.120 mg/L Hardness-dependent
Total copper 0.0332 mg/L 0.014 mg/L 0.020 mg/L Hardness-dependent
pH 6.0 – 9.0 5.0 – 9.0 5.5 – 9.0 6.0 – 9.0
Total suspended solids 100 mg/L — 100 mg/L 100 mg/L
Oil & grease 15 mg/L 10 mg/L 10 mg/L 15 mg/L

A TMDL on your receiving water can set limits well below these. EPA MSGP zinc and copper are hardness-dependent — zinc typically falls between 0.037 and 0.260 mg/L. Verify against your own permit and receiving water before you rely on any number here.

Frequently Asked

No. Construction sites operate under a different permit with different inspection requirements — phase of construction, perimeter controls, track-out, washout areas. If you're building, you need a CGP checklist. This one is for permitted industrial facilities.

It's built around the structure common to the California IGP, Washington's ISGP, Oregon's 1200-Z, and the EPA MSGP. The observation categories and BMP requirements are broadly consistent across the four. Specific thresholds and frequencies are not — check yours.

No. Download it.

Yes. It's a fillable PDF with 226 form fields. Complete it on a phone or tablet during the walk, save it, and file it. It also prints clean.

Most industrial stormwater permits require five years, retained on site with the SWPPP and available on request. Save each completed form the day the inspection is performed.

Use it however's useful. If you want a version set up with your facility's discharge locations and BMPs pre-filled, get in touch.

Talk to Someone Today

We know compliance can be a headache. Reach out to us via phone, email or contact form and get started.

talk to a stormwater management engineer

Found Something a Broom Won't Fix?

Walk your site with the checklist. If what you find is a housekeeping problem, you've saved yourself a phone call.

If the same discharge location keeps showing you the same thing, the problem is upstream of housekeeping. We've been building stormwater treatment — biofilters, catch basin inserts, filter socks, custom systems — for facilities across the country, and we'll tell you when you don't need one.

Jeff Pettey, Process Engineer

(206) 799-3296 · jeff@gullywasher.com

download the checklist

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